1. Technical Field
The invention relates to an optical apparatus. Particularly, the invention relates to a light source module and a projection apparatus.
2. Related Art
Along with development of display technology, besides that a projection apparatus uses an ultra high pressure lamp (UHP lamp) emitting a white light in collaboration with a color wheel to sequentially produce a red light, a green light and a blue light in order to achieve a color image frame of the projection apparatus, a light-emitting diode (LED) is further developed to serve as a light source of the projection apparatus. However, a light-emitting efficiency of the LED has a limitation, and in recent years, in order to break the limitation of the light-emitting efficiency of the LED, a technique of using laser to excite phosphor powder to produce the pure color light source required by the projection apparatus is gradually developed.
Regarding a known laser projection apparatus, in a light source design, a blue-ray laser is used to excite fluorescent powder of different positions on a color wheel, so as to respectively produce the red light and the green light. Since the red light and the green light are produced by exciting the fluorescent powder through the blue-ray laser, such optical design can reduce usage of red LEDs and green LEDs.
However, the blue-ray laser cannot be directly guided to a light combining system of the light source for utilization, so that usage efficiency of the high intensity and high purity laser light source is decreased.
Taiwan Patent Publication No. 201126254 discloses a projection apparatus including a laser light source and a wavelength conversion element. Taiwan Patent Publication No. 201100864 discloses an optical device having a characteristic of light offset according to different light incident angles. Moreover, U.S. Patent Publication No. 20110096300 discloses a projection apparatus including an excitation light irradiation device and a fluorescent light-emitting device.